Let’s go over some things, shall we?

Jenny was originally designed to be a shape-shifting superhero; her “pigtails” are rocket thrusters, and her entire body can morph and shift to create weapons. Given her standard appearance is more to look like a humanoid girl, it seems reasonable that that’s an appearance she chose, rather than her default, especially because we know she can modify her appearance however she likes, albeit restricted to her two base colors unless she gets a new paint-job.
Though her mother learns to be more supportive of her later on, Jenny was originally confined to house arrest save for doing her job, supposedly because the world around her wouldn’t accept her.
She is canonically six-foot-six, which is rather tall, though it seems the average height of humanity has also gone up. So it’s not too uncommon for other men to be taller than her, but she’s also taller than most people. She has so far only dated other men who are taller than her.
She gains two different disguises for looking human. The first one doesn’t pass at all, while the second passing one convinces her to behave like a normal human girl, whispering into her ear to not only look, but behave like a “normal” girl, even if it’s not in her best interests.
It’s evidently quite common for androids to be made from different base personality points- Kenny, a boy she dated for a little while, was a re-purposed dog robot, and still carried over some of his dog traits.
The two most popular girls in school specifically have it out for her, because she’s a robot “pretending” to be a girl.
Jenny is allowed to play in her high school’s male football team.